Bo-Cheng Kuo1; 1National Taiwan University

Change detection is of considerable importance in daily life. Successful detection of changes depends on the ability to compare the preceding visual short-term memory (VSTM) representations with the incoming perceptual events. However, the neural substrates underlying the comparison process for detecting feature-binding changes remain unclear. Here I investigate the neural mechanisms for the comparison process in successful detection of feature-binding changes using functional magnetic resonance imaging (fMRI, N = 18) and electroencephalography (EEG, N = 18). Participants performed a change detection task. The type of change (color feature and color-location binding) was manipulated to test whether change type during the comparison process can affect neural responses for supporting successful change detection. In the fMRI experiment, I found a distributed and extensive activation in the prefrontal-parietal neural network for successful change detection versus correct rejection. The fMRI results also revealed stronger activation in the prefrontal and parietal cortices whilst contrasting the binding-change trials with the feature-change trials. In the EEG experiment, I observed significant differences between the binding-change and the feature-change trials, with increased theta activity (3-7 Hz) over right frontal, parietal and temporal electrodes, between 380 ms and 520 ms for the comparison process. In conclusion, these results support the notion that top-down control mechanism is necessary to compare VSTM representations with perceptual inputs when change detection requires comparison of relational information, such as feature binding.